The Republican presidential candidate, Mitt Romney, was forced to apologise today, just hours after the Washington Post reported that he had held down a gay classmate, and cut off his bleached blond hair when he was a student at an elite private school.

According to the report, he bullied his classmate, John Lauber, when both were students at a well-known boarding school in the wealthy suburb in Detroit, Bloomfield Hills. Mr Lauber, who is deceased, was gay, and this, the Post suggested, might have been the reason he was bullied.

Five of Mr Romney’s classmates recalled Mr Lauber’s eyes “filling with tears.” They also remembered another incident where he shouted “atta girl” at a different student, who came out, years later as gay.

In a hastily arranged interview with Fox News radio, Mr Romney apologised to classmates he may have offended by “hijinks and pranks during high school,” but insisted that he didn’t know who was gay. “The people involved didn’t come out of the closet until years later,” he said.

Asked specifically about Mr Lauber, he said that he did not remember the incident in question, adding: “I certainly don’t believe that I thought the fellow was homosexual. That was the furthest thing from our minds back in the 1960s.”

The timing of the Post report is thought to be significant, coming as it does just a day after Obama became the first US president to support equal marriage for gay couples. Reacting to his announcement, Mr Romney reaffirmed his position that he thought marriage was between one man and one woman.